This pump is like all Suction Pumps limited to pumping lifts of a maximum of 8 m. It is not recommended to go deeper than 6-7 m. The No 6 Pump is not designed for a high daily output; it is rather a family or small community pump. If the foot valve looses its priming, water needs to be added to start the pumping again. This includes the danger of contamination.
====The mode of operation of a Suction Pump====
In a “suction” pump, the cylinder is above the water table, usually near the top of the pump head. The rising main extends below the water table.
When the pump is operated, during the upwards stroke it appears that water gets “sucked up” through the rising main into the cylinder. Rather, the atmospheric pressure forces the water into the area of low pressure underneath the piston.
The theoretical limit to which the atmospheric pressure can push up water is 10 meters. In practice, suction pumps can be used to lift water up to about 7 to 8 meters.
A suction pump needs to be full of water before it can be operated. That means the pump needs to be ''primed''. In regular practice, water has to be poured into the pump head by the operator, every time the pump is emptied by a leaking foot valve.
Thus, the danger exists that the well can be contaminated through polluted water used for priming.
The advantage of suction pumps is that the cylinder is normally above the level of the soil (above ground). For maintenance, the replacement of seals and valves can be easily performed with few tools.
==Suitable conditions==